The problem you're running into is the fact that the power table doesn't automatically paint unless an internal event within the table triggers it. You will need to do something like this from the dropdown's property change event handler:
if event.propertyName == 'selectedIndex':
powerTable = # get the power table component
# trigger a repaint
powerTable.table.model.fireTableDataChanged()
See this post for a more information related to this topic.